NAT Instances - gives internet access to instances in [[private subnet]]s. Old, must be setup in a [[public subnet]], disable Source / Destination check flag.
NAT Gateway - managed by AWS, provides [[scalable internet access]] to private instances, [[IPv4]] only
VPC Flow Logs: Can be setup at the VPC / Subnet / [[ENI]] Level for ACCEPT and REJECT traffic, helps identifying attacks, analyse using AWS Athena or [[CloudWatch Logs Insights]]
Bastion Host: Public instance to [[ssh]] into, that has SSH connectivity to instances in [[private subnet]]s